Plaque-forming cell capability in the senescent

The number of plaque-forming cells (PFC) developed in pokeweed mitogen (PWM)-activated unfractionated or T/B separated, 4:1 reconstituted cultures of peripheral blood lymphocytes (PBL) with well-characterized subpopulations obtained from healthy, aged subjects was compared to that of young blood donors. The absolute number of PBL in the aged was reduced by 36%, and the percentage of sheep erythrocyte-rosette-forming cells (E-RFC) by 27%, compared to the percentage obtained in young donors. The IgM-, IgG- and IgA-immunoglobulin (Ig) secretion was monitored with a protein A PFC assay. The number of PFC in PBL cultures of the aged was 58% of the number found in cultures of the young controls. The number of PFC generated in cultures of autologous irradiated T and untreated B cells showed a 104% increase in the aged whereas a 63% increase was obtained using cells from young individuals. Co-cultures of young B cells with untreated or irradiated young or aged T cells showed a significant rise in the PFC response in cultures with irradiated aged T cells, while an equal number of PFC was generated in cultures of young B cells with young or aged untreated T cells. Our results demonstrate a decreased number of PBL, especially T cells, an impaired B cell function and a pronounced enhancement of the PFC response in cultures of irradiated aged T cells and young or aged B cells, whereas the T helper function of untreated cells was found to be normal. The influence of monocytes on the PFC response did not differ in the two groups.     

The Heritability of Depression Symptoms in Elderly Danish Twins: Occasion-Specific Versus General Effects

Depression symptomatology was assessed up to four times at 2-year intervals on a sample of 2100 Danish twins initially aged 70 years and older. Data were analyzed using the biometric growth model approach proposed by Neale and McArdle (2000). Results show that occasion-specific depression is moderately and equally heritable in men and women (occasion-specific estimates of heritability ranged from 22% to 37%). Estimates of phenotypic variance, genetic variance, and heritability did not vary systematically across waves. In the best-fitting growth model, depression symptomatology was accounted for by two factors: (1) a level (i.e., average) effect that was highly heritable (estimate of 69% in women and 64% in men) and reflected overall vulnerability, and (2) a residual effect that was nonheritable and reflected occasion-specific circumstances that could either exacerbate or moderate inherited vulnerability. Attempts to identify specific genetic contributions to depression might profitably focus on average levels across multiple assessments, while attempts to identify specific environmental effects might profitably focus on deviations about this average.     

高师贫困生自我效能感与主观幸福感的特点及关系研究

目的分析高师贫困生自我效能感、主观幸福感的特点及关系，为心理健康教育提供依据。方法采用一般自我效能感量表、生活满意度量表、快乐感量表，对218名贫困生和216名非贫困生进行测查。结果①高师贫困生生活满意度、快乐感显著低于非贫困生（t=4．811，P〈0．001；t=2．504，P〈0．05），自我效能感差异不显著。②高师贫困生自我效能感存在性别差异（t=2．117，P〈0．05），男生的自我效能感显著高于女生；生活满意度年级差异显著（F=3．547，P〈0．05），大一学生的生活满意度显著高于大二和大三学生，大二和大三之间的差异不显著。③高师贫困生自我效能感与生活满意度、快乐感呈显著正相关（r=0．349，P〈0．01；r=0．436，P〈0．01）。自我效能感水平越高，幸福感越强。结论高师贫困生主观幸福感相对较低，自我效能感与主观幸福感显著相关，通过提升自我效能感水平可以增强主观幸福感。     

Detection of radiolabelled bone marrow cells bearing surface ace immunoglobulins by combined autoradiography and immunoperoxidase

A method is described for the simultaneous detection of radiolabelled bone marrow cells bearing surface immunoglobulins by combined autoradiography and immunoperoxidase. Bone marrow cells from normal CBA mice prelabelled in vivo with ¹²⁵IUDR or exposed in vitro to [³H]thymidine were incubated with rabbit anti-mouse immunoglobulins under capping conditions, washed, cytocentrifuged and treated with methanol and hydrogen peroxide to destroy endogenous peroxidase. Cells were then covered with peroxidase-conjugated goat anti-rabbit immunoglobulins, washed, treated with diaminobenzidine a and hydrogen peroxide and finally covered with autoradiographic stripping film and exposed for different times. Peroxidase-positive cells were typically capped and those radiolabelled had autoradiographic silver grains overlying the nucleus.     

Effect of age on serum immunoglobulin G subclass antibody responses to inactivated influenza virus vaccine

We previously reported an age-associated impairment of serum immunoglobulin G (IgG) antibody responses to inactivated influenza virus vaccine. The present study extends these observations by examining the IgG subclass distribution of vaccine responses measured by enzyme linked immunosorbent assay in healthy adults aged <40 (young), 40–64 (middle-aged), and ?65 (elderly) years. Serological responses in all age groups showed antibodies that were predominantly IgG1 and secondarily IgGS. Influenza antigen-specific IgG4 titers did not change following vaccination, and antibodies of the IgG2 subclass were not detected in any serum specimens. Aging was associated with a significant impairment of IgG1, but not of IgGS, antibody production. Relative differences in the magnitude and frequency of response between IgG1 and IgGS subclasses, which were present in young and middle-aged adults (viz., IgG1 > IgGS), were less apparent in the elderly. This observation was confirmed in a second analysis of IgG subclass-specific responses in a separate cohort of elderly vaccinees. These results suggest that the age-related impairment of humoral responses to inactivated influenza virus vaccine is primarily accounted for by differences in IgG1 antibody production, and that IgGS antibodies make up a larger proportion of the overall serologic response in the elderly than they do in younger persons. © 1994 Wiley-Liss, Inc.     

Role of Cachexia and Fragility in the Patient Candidate for Cardiac Surgery

Frailty is the major expression of accelerated aging and describes a decreased resistance to stressors, and consequently an increased vulnerability to additional diseases in elderly people. The vascular aging related to frail phenotype reflects the high susceptibility for cardiovascular diseases and negative postoperative outcomes after cardiac surgery. Sarcopenia can be considered a biological substrate of physical frailty. Malnutrition and physical inactivity play a key role in the pathogenesis of sarcopenia. We searched on Medline (PubMed) and Scopus for relevant literature published over the last 10 years and analyzed the strong correlation between frailty, sarcopenia and cardiovascular diseases in elderly patient. In our opinion, a right food intake and moderate intensity resistance exercise are mandatory in order to better prepare patients undergoing cardiac operation.     

Human myeloma light chains with increased molecular weight: high frequency among lambda chains

The discovery of a human myeloma protein comprising a kappa L-chain with an increased mol. wt of 30,000) (Bouvet et. al., 1980) prompted investigations on the incidence of such heavier L-chains among other human myeloma proteins. In 105 samples examined, 34 were found to have L-chains heavier than normal (23,000-24,000), ranging from 25,000 up to 31,000, and five of lighter mol. wt (21,000-22,000). These mol. wt abnormalities were detected by electrophoresis in sodium dodecyl sulfate 10% polyacrylamide gels (SDS-PAGE) after reduction with 2-mercaptoethanol. The mol. wt of three of the heavier kappa or lambda chains was also estimated by filtration through a Sephadex G100 column and by sedimentation equilibrium. All three methods indicated a mol. wt increase of about 15-25% as compared with the usual mol. wt. The distribution of the high mol. wt chains among all L-chains examined was found to be 11 out of 62 kappa chains (17.7%) and 23 out of 43 lambda chains (53%) (P less than 0.001). A preferential association of such L-chains with H-chains producing multiple bands in SDS-PAGE (P less than 0.01) and an association between multiple L-chain and multiple H-chain band (P less than 0.05) were also observed. In contrast, no abnormal L-chain was found in immunoglobulins from normal subjects. Spontaneous degradation of the normal H-chains sometimes yielded fragments of 30,000 mol. wt. These fragments were easily distinguishable from abnormal L-chains. The nature of extra mol. wt in heavy L-chains was investigated for the presence of carbohydrate moiety. Four large and three normal size L-chains were examined for amino-sugar and sialic acid content. A small amount (one residue per molecule) of amino-sugar was detected only in two normal and two heavy L-chains, whereas sialic acid was only found in the heaviest (27,000-30,000) L-chains (Lh) and in small percentage (one or two residues per molecule). Total sugar estimation in one Lh chain indicated a proportion not exceeding three or four residues per L-chain (mol. wt 1,000) and this is insufficient to explain the 15-25% (3,600-6,000) mol. wt increase. It is therefore possible that, at least in some heavy myeloma L-chains, an additional peptide is expressed. Whatever the nature of the increase it would be of interest to elucidate whether this is a marker of malignant process or of an intermediate step of normal Ig synthesis.     

Stability of Natural Self-Reactive Antibody Repertoires During Aging

We have used a quantitative immunoblotting technique to analyze the repertoires of self-reactive antibodies in serum samples obtained from the same five healthy adults over a 25-year interval. The average age of the donors was 43 years at the time of the first serum sample and 69 years at the time of the second serum sample. The antibody repertoires of IgM and IgG were found to be strikingly similar among individuals in both early and late samples. Densitometric profiles of self-reactivity of serum IgM and of purified serum IgG remained unchanged over the 25-year interval. The total reactivity of serum IgG decreased significantly over the 25-year period. The observed stability of the natural self-reactive IgM and IgG antibody repertoires with aging supports the view that autoreactive B cells in the normal immune system are positively selected for reactivity with a limited set of immuno-dominant self-antigens throughout life.     

Bioelectrical impedance methods in clinical research: a follow-up to the NIH Technology Assessment Conference

In 1994, the National Institutes of Health (NIH) convened a Technology Assessment Conference "to provide physicians with a responsible assessment of bioelectrical impedance analysis (BIA) technology for body composition measurement." In 1997, Serono Symposia USA, Inc., organized an invited panel of scientists and clinicians, with extensive research and clinical experience with BIA, to provide an update. Panel members presented reviews based on their own work and published studies for the intervening years. Updates were provided on the single and multifrequency BIA methods and models; continued clinical research experiences; efforts toward establishing population reference norms; and the feasibility of establishing guidelines for potential diagnostic use of BIA in a clinical setting. This report provides a summary of the panel's findings including a consensus on several technical and clinical issues related to the research use of BIA, and those areas that are still in need of additional study.